Sighting devices, such as rifle scopes, are typically equipped with one or more adjustment mechanisms that allow a shooter to change a setting of a reticle for aiming at a specific target. The adjustment mechanisms may change adjustment of, for example, elevation, windage (e.g., crossrange), or parallax of the sighting device. Adjustment mechanisms typically include an adjustment knob that may be rotated when a change to the setting of the reticle is desired. A cover cap may be employed to prevent unintentional rotation by the adjustment knob after adjusting the reticle to a desired setting. The cover cap may be removed each time the shooter wants to adjust the setting of the reticle. In addition to creating a potential for loss of the cover cap, removing the cover cap for each adjustment can be time consuming when a shooter wants to quickly change the reticle setting. Some adjustment mechanisms may require that the knob be raised to permit rotation by the adjustment knob, and lowered to prevent rotation of the adjustment knob due to friction between two or more components. However, such raising and lowering of the adjustment knob reduces the lifespan and reliability of the adjustment mechanism over time.